This is a regression, however I first noticed it at least a month or two ago, but could never reproduce it until now. This happens particularly with PNGs although I don't believe that it is limited to them (at least from what I have experienced.) Steps to reproduce. 1. Load the above URL. 2. Scroll the page up and down rapidly. Alt+Tabbing to a window that overlaps the area and the Alt+Tabbing back to Mozilla will show a correctly painted image. Reproducable: Always Observation: The image is wrapped vertically (depending on the time of repaint.) Details: Mozilla Win32 Nightly Build - 2002031103 (latest-trunk) Video: 1280x1024x16bpp (Win2K)
Created attachment 73531 [details] Another different rendering Shows another (different) result from scrolling
Created attachment 73532 [details] Another different rendering Shows another (different) result from scrolling
*** This bug has been marked as a duplicate of 83289 ***
Are you sure this is a duplicate?
This definitely isn't a duplicate. If you actually look at the screenshots, it's a totally different bug. This one is causing the images to wrap vertically, the other one was causing white stripes.
Based on Comment #7
If it's worth a "me too" comment, I was just about to report this too in 2002030803. (Loading http://thurman.org.uk/thomas/pics/polygons/test and scrolling down to the bottom looks like http://thurman.org.uk/thomas/pics/polygons/bugzilla ; making Mozilla repaint, by switching to another application and back, shows it correctly.)
*** This bug has been marked as a duplicate of 121230 ***
No this is not the same. Bug 121230 deals only with PNG images. This problem also occurs with GIFs and JPEGs.